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Mikroorganisme dalam siklus biogeokimia

Mikroorganisme dalam siklus biogeokimia. Oleh: Dr. Ratu Safitri, MS. Laboratorium Mikrobiologi. Jurusan Biologi F-MIPA Universitas Padjadjaran. Lingkup Materi :. Ikhtisar Siklus Biogeokimia : - Siklus N dan Reaksi dalam siklus - Siklus O - Siklus P - Siklus C.

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Mikroorganisme dalam siklus biogeokimia

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  1. Mikroorganismedalamsiklusbiogeokimia Oleh: Dr. Ratu Safitri, MS Laboratorium Mikrobiologi. Jurusan Biologi F-MIPA Universitas Padjadjaran

  2. LingkupMateri: • IkhtisarSiklusBiogeokimia : - Siklus N danReaksidalamsiklus - Siklus O - Siklus P - Siklus C

  3. Dasardarikonsepsiklusbiogeokimia • Semua materi siklus tidak diciptakan atau dihancurkan • Sehubungan karena bumi adalah suatu sistem tertutup, maka semua hal yang berada di dalamya akan dalam suatu siklus. • Siklus Biogeokimia: perbahan atau sklus materi dalam suatu sistem lingkungan.

  4. Jenismateri yang beredar • Element kimia (carbon, nitrogen, oxygen, sulfur , Phosphor) atau molekule air . • Makronutient : diperlukan pertukaran dalam jumlah yang besar, misal : potassium , calcium , iron , magnesium • Mikronutrien beredar dalam jumlah yang sangat kecil, misalnya: boron (tanaman hijau) copper (untuk aktifitas ensim)molybdenum (nitrogen-fixing bacteria)

  5. Earth’s ecosystems are maintained by a constant influx of energy Transformation Loss of Energy Solar Energy Autotroph Herbivore Carnivore Respiratory Loss

  6. Decomposition Respiration Excretion Biogeochemical Cycles Biotic Uptake Cycling of chemical elements between living and non-living portions of the earth’s ecosystems Abiotic

  7. Biogeochemical Cycle: Siklusutama yang akandibahas: • Siklus nitrogen • Siklus oxygen • Siklus phosphorus • Siklus carbon Sirkulasimolekulkimiadalamsiklusbiogeokimiadaninteraksinyadalamsiklusadlahsangatpentinguntukmemeliharaekosistemterestrial, air tawar, danekosistemlaut. Perubahaniklim global, temperatur, hujan, dannkestabilanekosistemsangattergantungpadasiklusbiogeokimia.

  8. Siklus N

  9. Nitrogen beredardi Tanah • Komposisi N udara: 80% • Nitrogen beredar dalam • peredaran : • (a). Bakteri dalam tanah • akan merubah nitrat menjadi gas ke udara (denitrifikasi) • (b) Dengan adanya cahaya, sejumlah • nitrogen dioksidasi dan bergabung dengan air membentuk asam dan akan jatuh dalam bentuk hujan. • Tanaman akan mengambil nitrat dan mengubahnya menjadi bahan protein yang akan diantarkan oleh karnivora dan herbivora dalam rantai makanan. • Ketika organisma mengelurakan limbah, nitrogen akan dikembalikan ke lingkunga. Ketika biota mati, akan didekomposisi dan dikonversikan menajdi amoniak.

  10. Surface water Low [NH4] Oxidized layer Biodegradation Reduced soil layer Slow Diffusion C/N <20 C/N >20 [NH4] HIGH

  11. Surface water nitrification Low [NH4] Oxidized layer [NO3] high Reduced soil layer Slow Diffusion [NH4] HIGH

  12. N2 Surface water Oxidized layer [NO3] high Leaching Reduced soil layer [NO3] Low Denitrification

  13. Nitrogen Fixation Nodules on plant roots

  14. Reaksi-reaksidalamSiklus Nitrogen

  15. Sumber N • Lightning • Inorganic fertilizers • Nitrogen Fixation • Animal Residues • Crop residues • Organic fertilizers

  16. Forms of Nitrogen Roles of Nitrogen • Urea  CO(NH2)2 • Ammonia  NH3 (gaseous) • Ammonium  NH4 • Nitrate  NO3 • Nitrite  NO2 • Atmospheric Dinitrogen N2 • Organic N • Plants and bacteria use nitrogen in the form of NH4+ or NO3- • It serves as an electron acceptor in anaerobic environment • Nitrogen is often the most limiting nutrient in soil and water.

  17. Global Nitrogen Reservoirs

  18. Nitrogen is a key element for • amino acids • nucleic acids (purine, pyrimidine) • cell wall components of bacteria (NAM).

  19. Nitrogen Cycles • Ammonification/mineralization • Immobilization • Nitrogen Fixation • Nitrification • Denitrification

  20. N2 N2O NH4 NO2 R-NH2 NO NO2 NO3

  21. Ammonification or Mineralization N2 N2O NH4 NO2 R-NH2 NO NO2 NO3

  22. Mineralization or Ammonification • Decomposers: earthworms, termites, slugs, snails, bacteria, and fungi • Uses extracellular enzymes  initiate degradation of plant polymers • Microorganisms uses: • Proteases, lysozymes, nucleases to degrade nitrogen containing molecules • Plants die or bacterial cells lyse  release of organic nitrogen • Organic nitrogen is converted to inorganic nitrogen (NH3) • When pH<7.5, converted rapidly to NH4 • Example: Urea NH3 + 2 CO2

  23. Immobilization • The opposite of mineralization • Happens when nitrogen is limiting in the environment • Nitrogen limitation is governed by C/N ratio • C/N typical for soil microbial biomass is 20 • C/N < 20Mineralization • C/N > 20 Immobilization

  24. Nitrogen Fixation • Energy intensive process : • N2 + 8H+ + 8e- + 16 ATP = 2NH3 + H2 + 16ADP + 16 Pi • Performed only by selected bacteria and actinomycetes • Performed in nitrogen fixing crops (ex: soybeans) N2 N2O NH4 NO2 R-NH2 NO NO2 NO3

  25. Microcystis Anabaena Microorganisms fixing • Azobacter • Beijerinckia • Azospirillum • Clostridium • Cyanobacteria • Require the enzyme nitrogenase • Inhibited by oxygen • Inhibited by ammonia (end product)

  26. Rates of Nitrogen Fixation

  27. Bacterial Fixation • Occurs mostly in salt marshes • Is absent from low pH peat of northern bogs • Cyanobacteria found in waterlogged soils

  28. Nitrification Two step reactions that occur together : • 1rst step catalyzed by Nitrosomonas 2 NH4+ + 3 O2 2 NO2- +2 H2O+ 4 H+ • 2nd step catalyzed by Nitrobacter • 2 NO2- + O2  2 NO3- N2 N2O NH4 NO2 • Optimal pH is between 6.6-8.0 • If pH < 6.0  rate is slowed • If pH < 4.5  reaction is inhibited R-NH2 NO NO2 NO3

  29. Denitrifikasi • Removes a limiting nutrient from the environment • 4NO3- + C6H12O6 2N2 + 6 H20 • Inhibited by O2 • Not inhibited by ammonia • Microbial reaction • Nitrate is the terminal electron acceptor N2 N2O NH4 NO2 R-NH2 NO NO2 NO3

  30. Atmosphere Organic Matter Plant/Microbial Sink 2NH4+ + 2OH- NO3- Pool Interactive Nitrogen Cycle Industrial Processes Plant and Animal Residues Lightning, Rainfall N2 Fixation Fertilizer Volatilization Plant Loss R-NH2 + Energy + CO2 R-NH2 + H2O N2, N2O, NO R-OH + Energy + 2NH3 2NH4+ + 2OH- Soil exchange sites Back to Intro Page Leaching 2NO2- + H2O + 4H+

  31. Back to Intro Page 3H2 + N2 2NH3 GLOBAL WARMING ATMOSPHERE N2O NO N2 INDUSTRIAL FIXATION LIGHTNING, RAINFALL N2 FIXATION PLANT AND ANIMAL RESIDUES HABER BOSCH (1200°C, 500 atm) SYMBIOTIC NON-SYMBIOTIC MESQUITE RHIZOBIUM ALFALFA SOYBEAN BLUE-GREEN ALGAE AZOTOBACTER CLOSTRIDIUM MATERIALS WITH N CONTENT > 1.5% (COW MANURE) MATERIALS WITH N CONTENT < 1.5% (WHEAT STRAW) FERTILIZATION PLANT LOSS AMINO ACIDS MICROBIAL DECOMPOSITION NH3 AMMONIA VOLATILIZATION IMMOBILIZATION AMINIZATION HETEROTROPHIC ORGANIC MATTER R-NH2 + ENERGY + CO2 BACTERIA (pH>6.0) FUNGI (pH<6.0) pH>7.0 R-NH2 + H2O AMMONIFICATION NH2OH IMMOBILIZATION R-OH + ENERGY + 2NH3 N2O2- Pseudomonas, Bacillus, Thiobacillus Denitrificans, and T. thioparus 2NH4+ + 2OH- MICROBIAL/PLANT SINK MINERALIZATION + NITRIFICATION FIXED ON EXCHANGE SITES +O2 NO2- Nitrosomonas DENITRIFICATION NO3- POOL NITRIFICATION 2NO2- + H2O + 4H+ OXIDATION STATES Nitrobacter + O2 DENITRIFICATION LEACHING LEACHING VOLATILIZATION NITRIFICATION ADDITIONS NH3 AMMONIA -3 NH4+ AMMONIUM -3 N2 DIATOMIC N 0 N2O NITROUS OXIDE 1 NO NITRIC OXIDE 2 NO2- NITRITE 3 NO3- NITRATE 5 Joanne LaRuffa Robert Mullen Wade Thomason Susan Mullins Shannon Taylor Heather Lees Department of Plant and Soil Sciences Oklahoma State University TEMP 50°F LEACHING LEACHING LOSSES OXIDATION REACTIONS LEACHING REDUCTION REACTIONS pH 7.0

  32. SiklusOksigen

  33. Tanaman menggunakan energi matahari untuk mengkonversikan karbondioksida dan air menjadi karbohidrat dan oksigen melalui fotositesis. 6CO2 + 6H2O + energy → C6H12O6 + 6O2 • Organisma fotosintetik berperan dalam siklus oksigen termasuk tanaman , phytoplankton di laut. Biota laut cyanobacteriaProchlorococcus ditemukan tahun 1986. • Hwan membentuk setengah siklus dari oksigen yang digunakan untuk memecah karbohidrat menjadi energi dalam proses respirasi. O2 + carbohydrates → CO2 + H2O + energy

  34. Siklus P

  35. Siklus P diLautan

  36. Siklus P didalam Tanah

  37. The phosphorus cycle describes the movement of phosphorus through the lithosphere, hydrosphere, and biosphere. The atmosphere does not play a significant role, because phosphorus and phosphorus-based compounds are usually solids at the typical ranges of temperature and pressure found on Earth. • Phosphorus normally occurs in nature as part of a phosphate ion, consisting of a phosphorus atom and some number of oxygen atoms, the most abundant form (called orthophosphate) having four oxygens: PO43-. Most phosphates are found as salts in ocean sediments or in rocks. Over time, geologic processes can bring ocean sediments to land, and weathering will carry terrestrial phosphates back to the ocean.

  38. Plants absorb phosphates from the soil and phosphate enters the food chain. After death, the animal or plant decays, and the phosphates are returned to the soil. Runoff may carry them back to the ocean or they may be reincorporated into rock. • The primary biological importance of phosphates is as a component of nucleotides, which serve as energy storage within cells (ATP) or when linked together, form the nucleic acids DNA and RNA. Phosphorus is also found in bones, and in phospholipids (found in all biological membranes). • Phosphates move quickly through plants and animals; however, the processes that move them through the soil or ocean are very slow, making the phosphorus cycle overall one of the slowest biogeochemical cycles.

  39. SiklusKarbon

  40. Usually thought of as four major reservoirs of carbon (the atmosphere, the terrestrial biosphere - which includes freshwater systems and non-living organic material, such as soil carbon -, the oceans with dissolved inorganic carbon and living and non-living marine biota, and the sediments which includes fossil fuels) interconnected by pathways of exchange. • The exchanges between reservoirs, occur because of various chemical, physical, geological, and biological processes. The ocean contains the largest active pool of carbon near the surface of the Earth, but the deep ocean part of this pool does not rapidly exchange with the atmosphere.

  41. The global carbon budget is the balance of the exchanges (incomes and losses) of carbon between the carbon reservoirs or between one specific loop (e.g., atmosphere - biosphere) of the carbon cycle. IN THE OCEAN: • The seas contain around 36000 gigatonnes of carbon, mostly in the form of bicarbonate ion. Inorganic carbon, that is carbon compounds with no carbon-carbon or carbon-hydrogen bonds, is important in its reactions within water. This carbon exchange becomes important in controlling pH in the ocean and can also vary as a source or sink for carbon.

  42. Carbon is readily exchanged between the atmosphere and ocean. In regions of oceanic upwelling, carbon is released to the atmosphere. Conversely, regions of downwelling transfer carbon (CO2) from the atmosphere to the ocean. When CO2 enters the ocean, carbonic acid is formed: • CO2 + H2O ⇌ H2CO3 • This reaction has a forward and reverse rate, that is it achieves a chemical equilibrium. Another reaction important in controlling oceanic pH levels is the release of hydrogen ions and bicarbonate. This reaction controls large changes in pH: • H2CO3 ⇌ H+ + HCO3−

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